System for automatically tying bundles



April 16, 1963 G. E. wlMMl-:R

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12 Sheets-Sheet 2 April 16, 1963 G. E. wxMMER SYSTEM FOR AUTOMATICALLYTYING BUNDLES Filed oct. e, 1960 12 Sheets-Sheet 3 `1NVNT01L Glen 5.Dzmmef April 16, 1963 G. E. wlMMl-:R 3,085,501

SYSTEM FOR AUTOMATICALLY TYING BUNDLES Filed Oct. 6. 1960 12Sheets-Sheet 4 TGJ5 GJ FIG. ./7

April 16, 1963 G. E. wlMMER 3,085,501

SYSTEM FOR AUTOMATICALLY TYING BUNDLES Filed Oct. 6, 1960 l2Sheets-Sheet 5 FIG. J9

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SYSTEM FOR AUTOMATICALLY TYING BUNDLES April 16, 1963 G. E. WIMMERSYSTEM FOR AUTOMATICALLY TYING BUNDLES Filed oct. 6, i960 FIG. Z5

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SYSTEM FOR AUTOMATICALLY TYING BUNDLES Filed Oct. 6, 1960 12Sheets-Sheet 12 United States Patent O 3,085,501 SYSTEM FGI!AUIMATICALLY 'IYING BUNDLES Glen E. Wimmer, Evanston, Ill., assigner toB. H. Bunn Company, Chicago, Ill., a corporation of Illinois Filed Get.6, 1960, Ser. No. 66,945 14 Claims. (Cl. 10G- 4) This invention relatesto a conveyorized system for tying bundles of letters or the like. Forpurposes of illustration it will be described with reference to itsapplication to handling mail in a post oiiice. Y

Incoming mail in a post otiice is generally sorted as to destination,and all letters having the same destination are assembled into a bundlewhich is then tied with a string to facilitate subsequent handlingthereof. A bundle of mail may be approximately 51/2 inches wide, 111/2inches long and 41/2 inches thick, these dimensions being the maximum-dimensions for the width and length of the envelopes handled and forthe thickness of the bundle into which the envelopes are assembled. Eachsuch bundle is tied in a tying machine which may be of the typedescribed in B. H. Bunn Patent No. 2,898,847 dated August 11, 1959. Suchmachines are adapted to tie a lbundle in one direction with a doublewrap', the operator then turning the bundle through 90 to effect a tyingof the bundle in a transverse direction. Such machines may also beequipped with a trip mechanism which initiates the operation of thetying mechanism when a -bundle of mail is placed over the trip mechanismand depressed to operate the trip mechanism.

The machines as heretofore constructed required that an operator beassigned to each machine, each such .operator bringing a bundle of mailto be tied to the machine and holding it on the machine While the bundlewas tied in one direction. He was then required to turn the tied bundlethrough 90, hold the turned bundle on the machine to effect a cross tiethereof, and then remove the cross tied bundle from the machine.

An object of this invention is the provision of a conveyorized system-for delivering sorted mail in bundles to a bundle-tying station wherethe bundle is automatically transferred from the conveyor to a tyingmachine, with means for automatically ejecting a tied bundle fromythemachine.

Another object of this invention is the provision of a transfermechanism for transferring a bundle of loose, untied mail from aconveyor to a tying machine without interrupting the continuousoperation of the conveyor.

Yet another object of this invention is the provision of a pair oftyingmachines each adapted to tie a bundle of loose mail in a directiontransverse to the other, with means for automatically transferring the`bundle from one machine to the other, thereby effecting an assemblyline operation of the tying machines.

As a more specific object, this invention has within its purview theprovision of a control mechanism for initiating the operation of a pairof bundle-tying machines, said control mechanism automatically renderinga machine inoperative unless a bundle to be tied is placed thereon.

As a further specific object, this invention provides a controlmechanism for operating transfer mechanisms and bundle-tying machines inproper sequence to effect a tie in two directions on said bundle, withmeans for automatically cutting out certain of the operations when nobundle is to be tied.

Yet another specific object of this invention is the provision of aconveyorized system of tying bundles of mail, said system incorporatinga conveyor unit for bringing mail sorted at one or more locations to acommon point, picking oit the sorted bundle from the moving conveyor andtransferring these one at a time to a first tying machine `for tying thebundles in one direction, transferring the bundles to a second tyingmachine for tying them in a direction transverse to the first tie, andfinally ejecting the tied bundle from the second machine.

These and other objects of this invention will become apparent from thefollowing detailed description of a preferred embodiment thereof whentaken together with the accompanying drawings in which- FIGURE l is aschematic plan view of the principal components of this invention;

FIG. 2 is a schematic elevational view of the units of FIGURE 1;

FIGS. 3, 5, 7 and 9, and FIGS. 4, 6, 8, 8a and 10 are, respectively,plan and elevational views of a first transfer mechanism forming part ofthis invention in the iirst stages of operation;

FIG. 11 is a fragmentary end elevational View of a first tying machineforming part of this invention showing a bundle hold-down mechanismthereof in operative condition;

FIG. lla is an enlarged view of an `element of the iirst tying machineshowing the placement of certain controls for the components of thisinvention;

FIGS. l2 and 13 are, respectively, simplified plan and elevational viewsof a second transfer mechanism forming part of this invention, showingthe movement of a tied bundle from one tying machine to an adjacenttying machine;

FIG. 14 is a fragmentary end elevational view of the second tyingmachine with the bundle hold-down mechanism thereof in operativecondition;

FIG. 14a is an enlarged view of an element of the second tying machine,showing the placement of certain other controls for the components ofsaid second tying machine;

FIGS. 15 and 16 are schematic front elevational views of the rst tyingmachine showing the failure of the trip mechanism thereof to operate inthe absence of a bundle thereon;

FIGS. 17 and 18 are end elevational views of the second tying machine(looking from the left of FIG. l) showing the failure of the tripmechanism thereof to operate in the absence of a bundle placed thereon;

FIGS. 19 and 20 are front elevational views of the iirst tying machineshowing the operation thereof when a bundle is placed thereon;

FIGS. 2l and 22 are end elevational views of the second tying machine(looking from the left of FIG. l) showing the operation thereof whenV abundle is placed thereon;

FIGS. 23 and 24 are, respectively, plan and front elevational views ofthe conveyor mechanism which carries bundles of mail to the vicinity ofthe tying machines;

FIG. 25 is an enlarged end elevational View of the conveyor mechanism(looking from the right of FIG. l) taken in section along line 25-25 ofFIG. l and showing one of the mail -bundle-supporting buckets and therollersupporting mechanism therefor;

FIG. 26 is a front elevational view in section, also on an enlargedscale, of one of the mail bundle-supporting b131ckets, the view beingtaken along line 26-26 of FIG. 2 l

FIG. 27 is an enlarged plan view of the transfer mechanisms and the twotying machines with the observer standing to the rear thereof andlooking toward the front as viewed in FIG. l

FIG. 28 is a rear elevational view of the transfer mechanisms and tyingmachines of FIG. 27 on substantially the same scale as FIG. 27;

FIG. 29 is a front elevational View of the transfer Pce 3 mechanism fortransferring a bundle of mail from the conveyor to the first tyingmachine said view being on a still larger scale than FIGS. 27 and 28;

FIG. 30 is a plan view in section of a portion of the transfer mechanismof FIG. 29;

FIG. 3l is an enlarged fragmentary rear elevational view of a sprocketof the conveyor, showing the relative placement for still other controlsfor certain elements of this invention;

FIGS. 32 and 33 are sections through typical valves for controlling theair cylinders used in the apparatus;

FIG. 34 is a schematic wiring diagram for the electrical components ofthe invention; and

FIG. 35 is a cycling diagram for the components of this invention.

Referring no-W to FIGS. l 4and 2 for a general description of theinvention, the system is comprised of a conveyor unit 4f), the functionof which is to bring sorted bundles of mail from the sorting stations ina post oflice to the tying machines, a first transfer mechanism 4l whichtakes the bundles from the conveyor 4t?, a first tying machine 42 towhich the bundles are transferred from conveyor 40 and on which the saidbundles are tied in one direction, a second transfer mechanism 43 whichremoves a tied bundle from the first tying machine 42, a second tyingmachine 44 to which the bundles are transferred from first tying machine42 and which ties said bundle in another direction, and a third transfermechanism 45 which removes a tied bundle from the second tying machine44 and eects it into a hopper or the like.

It is contemplated that the conveyor 4@ 'will be of such length and sodisposed as to run past a number of sorting stations in a post ofiice.The sorters will manually place each sorted bundle on conveyor 474i',which is equipped with spaced buckets 61, hereinafter to be described indetail, and in which each bundle is placed by the sorters with theenvelopes standing on edge and held by a suitable spring clamp. Theconveyor moves continuously toward the first transfer mechanism 4l.

The tying machines are designed to Wrap a length of twine around aplurality of envelopes while the envelopes are stacked upon one anotherwith their general planes in a horizontal position. The conveyor 40'therefore is arranged to have, first, a horizontal section 47 on whichthe envelopes are disposed upon their edges, and a vertical section 48which turns the envelopes through 90 to cause them to lie substantiallyparallel with the horizontal position in which they are to be tied.

It may be observed that when the bundle of envelopes is placed in abucket with the edges of the envelopes down, the envelopes will tend toalign themselves against the bottom of the bucket and thereby avoid aloose and misaligned tie.

The transfer mechanism 4l is required to pick off a bundle from thevertical section 4S of the conveyor while the bundle is movingdownwardly, and transfer such bundle to the first tying machine 42.Means hereinafter to be described are therefore provided for imparting avertical movement to the first transfer mechanism 4l in synchronism withthe vertical movement of the bundle to be removed from the conveyorwhile the removal thereof takes place, a horizontal movement into thebucket to .grasp the bundle of envelopes carried therein, a reversemovement in a horizontal direction to withdraw the bundle from thebucket, ay swinging movement in a horizontal plane to bring the bundleto a desired location on the first tying machine, and a finalwithdrawing movement and swinging movement to bring the transfermechanism into .position for grasping a second bundle. To effect asimplification of the controls for the system, the first transfermechanism is designed to run continuously with the conveyor 40 and to gothrough its cycle of movements whether or not there is a bundle of mailin each bucket. It is not desirable, however, to have the first tyingmachine 42 running continuously and hence means are provided,`

Yhereinafter to be described in detail, for preventing operation of thefirst tying machine when no bundle is placed thereon.

It is likewise undesirable for the second transfer mechanism 43 to runthrough its motions and for the second tying machine 44 and the thirdtransfer mechanism 4S likewise to run through their motions unless abundle is placed thereon. The second transfer mechanism 43 therefore istriggered to operate from the operation of first tying machine 42 sothat if the first tying mechanism or machine does not operate, thesecond transferring mechanism likewise will not operate.

Assuming, however, that a bundle of mail has been placed upon the firsttying machine 42 by transfer mechanism 41 and has been tied thereby inone direction, the operation of the first tying machine will cause anoperation of the transfer mechanism 43, which then pushes the tiedbundle to the table of the second tying machine 44. There a mechanismwill sense the presence of a bundle and will cause the bundle to be tiedin a direction crosswise of the first tie. The sensing mechanism for thesecond tying machine will be triggered by the operation of the firsttying machine so that if there is no bundle in the first tying machine,the sensing mechanism will not operate and the second machine, as wellas the third transfer mechanism, will be inoperative. In the event thatthe first machine operates, but for some reason there is amalfunctioning of the transfer mechanism 43, the sensing mechanism forthe second tying machine 44 will operate but will sense the absence of abundle and hence will prevent the automatic operation of the secondtying machine.

Assuming that the second tying machine has performed its tyingoperation, a control for the third transfer mechanism will be set inoperation and will cause the third transfer mechanism to remove the tiedbundle from the second tying machine and into a hopper or possibly toanother conveyor (not shown).

The transfer mechanisms and certain bundle holddown mechanismsassociated with the two tying machines, in the form chosen to illustratethis invention, are pov/ered by known readily available air cylinderscontrolled by ,electromagnetically operated valves which in turn areenergized by micro-switches disposed in the path of movement of a memberperforming an antecedent function. Thus, a first group of micro-switchescontrols certain movements of the first transfer mechanism and isoperated by an element or elements movable with the conveyor. A secondgroup of microswitches, operated by the movement of elements of theVfirst transfer mechanism, controls other movements of the first transfermechanism and initiates the movement of the hold-down mechanism of thefirst tying machine. A third group of switches, operated by elements ofthe hold-down mechanism for the first tying machine, controls theremaining movements of the first transfer machine to complete the cyclethereof. A fourth group of switches is operated by elements of the firsttying machine and releases the holddown mechanism of the first tyingmachine, operates the second transfer mechanism and engages the holddown mechanism of the second tying machine. A fifth group of switches isoperated by elements of the second tying machine and releases thehold-down mechanism thereof and operates the third transfer-mechanism.

The Conveyor Unit The details of construction of the conveyor unit 40are shown in FIGS. 23 to 26 inclusive, to which reference is now made.

`Conveyor unit 40 may comprise a frame 49 having parallel horizontallydisposed frame members 50 and 51 to Which are fastened oppositelydisposed channel-shaped tracks 52 and 53. Spaced endless chains 54 and55 are supported on horizontal pins 56 and 57 extending outwardly fromthe downwardly depending legs 53 and 59 of a base plate 60 which may bea casting. Said plate 60 extends slightly above frame members 50 and 5,1and supports a bucket 61 which may be made of sheet metal and may have abottom 62, a side wall 63 and a front wall 64. Bucket 61 is intended toreceive and carry a bundle of envelopes which is placed therein by themail sorter. Said front wall 64 is relieved or notched at its upper endas at 65 to expose the upper ends of the envelopes in the bucket to thepick-up elements of the rst transfer mechanism 41.

It may be noted that the front wall 64 slopes backward- 1y from theperpendicular to the bottom 62 as viewed in FIG. 26. The purpose of thisslope is to make certain that as the buckets move down the verticalsection of the conveyor, the envelopes will tend to slide toward thebottom 62 rather than in the opposite direction and fall out of thebucket. It is contemplated that as a bundle of envelopes is placed intoa bucket, the operator will push the bundle against side wall 63 tolevel the bundle somewhat at that end and that he will allow theindividual envelopes in the bundle to fall against the bottom 62 of thebucket and thus level olf the edges of the envelopes adjacent thereto.

Inasmuch as the rearwardly sloping wall 64 would tend to make theenvelopes fall over in that direction (i.e., to the left as viewed inFIG. 26), support for the envelopes is afforded by a finger spring 66riveted at one end to an L-shaped stamping 67 spot-welded to bucketbottom 62 at the corner of said lbottom farthest removed from side wall63 and front wall 64. Said inger spring 66, as viewed in FIG. 23, isS-shaped in section to provide a rounded surface at the free end thereofto bear against the bundle of envelopes and thereby to avoid cutting ortearing of the envelopes.

Each of the pins 54, 55 has mounted thereon an antifriction roller 68,69, which rides on the inside of the side flanges of the channel-shapedtracks 52, 53. At the forward end of tracks 52, 53 are sprockets 70 and71 which may be mounted on a common shaft 72 supported in spacedbearings 73 and 74 secured to frame 49. Said sprockets 70, 71 turn theconveyor chains downwardly over the vertical section 48 of the conveyor.A pair of drive sprockets 75 below sprockets 70 and 71 serves to turnthe conveyor chains backwardly away from the said vertical section 48and upwardly through guides 76 which then turn the chains in ahorizontal direction to rear sprockets 77 where the direction of thechain is reversed for `the horizontal section 47. Drive sprockets 75 aredriven from a motor 78 mounted on a platform 79 on `frame 49 andconnected to drive sprockets 75 through suitable reduction gearing andsprocket and chain mechanism shown schematically at 80.

The First Transfer Unit The details of the rst transfer mechanism areshown in FIGS. 27 28, 29 and 30, and will now be described.

Referring rst to FIG. 28, the first transfer mechanism 41 includes aclamping device 81 which seizes a bundle of mail from one of the buckets61 on the conveyor, a horizontally reciprocating mechanism 82 forwithdrawing a bundle from a conveyor bucket, a rotating mechanism 83which `swings mechanisms 81 and 82 about a vertical axs to deposit abundle on the rst tying machine 42 and a raising and lowering mechanism84 which moves the mechanisms -81 and 82 vertically to follow a movingbucket 61.

Clamping mechanism 81 is comprised of an L-shaped casting 85 on which isdisposed a pneumatic cylinder 86 of known construction with its axis ina vertical plane, the piston rod 87 of which is connected to a crossmember 46 on the ends of which are secured disk-shaped pads S8 and y89which contact the upper surface of the bundle to be seized. To the underside of casting 85 is secured a U-shaped stamping 90 having a shorthorizontal side 91 by which said stamping is secured to said casting 85,a vertically disposed back 92 and a horizontally disposed side V93 whichis longer than side 91 and extends gerierally under pads 88 Aand 89.'Ihe horizontal length of stamping is less than the horizontal length ofa bucket 61 on Vertical section 48, and the stamping is so placed withreference to the transfer mechanism that in the position in which itpicks off a bundle of mail, side 93 will be well within the notch 65 inthe bucket wall 64. Side 93, therefore, does not contact wall 64 of thebucket at any time.

The stamping 90 and the clamping mechanism 81 are sometimes hereinafterreferred to as the pick-olf head.

Horizontally reciprocating mechanism y82. is comprised of a frame member94, `also L-shaped, and having a base 95 secured to a splined shaft 96.Said frame member 94 supports a horizontal guide rod 97 which is securedat its right hand end (FIG. 28) to L-shaped frame casting 85.Immediately above guide rod 97 is mounted a pneumatic cylinder 9S ofknown construction, the piston rod 99 of which is also connected toL-shaped frame member 85. Guide rod 97 extends through base 95, and itsleft hand end 100 (FIG. 28) has a depending nger 10'1 secured thereto,the function of which is to operate a micro-switch in a mannerhereinafter to be described.

Rotating mechanism 83 is supported by various elements of the machineframe. The rst such element is a plate 102 which is secured at one endto a vertically ydisposed angle iron or the like 103 (FIG. 27), and atits other en-d to a casting 104 which in turn is secured to a verticallydisposed plate 105 appropriately secured to an `angle iron 106 forming apart of the lower portion of the maclnne frame. Said casting 104 is alsosecured to another angle iron 107 forming an upper part of the machineframe. Thus, casting 104 is rigidly supported from, and forms a part of,the machine frame.

`Casting 104 extends upwardly under base 95 of the horizontallyreciprocating mechanism S2 to provide a support for a first bearing 10Sfor shaft 96, a second bearing 109 for said shaft 96 being formed incasting 104 below and separated from bearing 108. Suitable antifrictionsupports (not shown) are provided in the supports for the shaft 96 topermit said shaft to rotate freely therein. Between bearings 108 and 109is disposed a hub member 110 which, `as shown in FIGS. 28 and 30, issplined to shaft 96 so that said shaft may move vertically with respectto said hub, but is constrained to rotate with said hub. Suitablespacers and thrust washers 111 are interposed between hub 110 and upperbearing 108 to prevent vertical movement of the hub with respect tocasting 104. An arm 112 extends radially outwardly from hub 110 and ispivoted at .113 to a piston rod 114 extending outwardly from a pneumaticcylinder 115 of known construction pivoted in turn at 116 to spaced ears117 secured to plate 102.

It may be apparent from the description thus far given of the rotatingmechanism 83 that when cylinder 115 is activated to reciprocate itspiston rod 114, arm 112 will be oscillated about the axis of shaft 96,and, through its splined connection therewith, will likewise oscillatesaid shaft. This, in turn, will impart the rotating movement to the base95 of frame member 94 which elects a swinging movement in a horizontalplane of the bundle carried by pick-off head 90.

The vertically movable mechanism 84 is comprised of a pneumatic cylinder118` of known construction disposed with its axis in a vertical positionand secured at its lower end to a bracket 119 mounted on plate 105, andat its upper end, to a bracket 120 likewise secured to plate 105. Thepiston rod 121 is secured through a connection e122 to the lower end 123of splined shaft 96.

Said connection 122 includes an anti-friction bearing 124 which allowsfree rotation of shaft 96 relative to connection 122 about the axis ofcylinder 118, but which prevents relative axial movement between shaft96 and connection 122. Thus cylinder 118 may be activated and inoperation to raise and lower shaft 96 at the same time that cylinder 115is activated to rotate said shaft.

The First Tying Machine The rst tying machine 42, as stated previously,may be of the type disclosed in the aforementioned B. I-I. Bunn PatentNo. 2,898,847 for Tying Machine granted August l1, 1959, modified:slightly to adapt it to use with the transfer mechanism 41. Thus, inthe machine disclosed in the aforesaid Bunn patent, a bundle-locatingmechanism, lsuch as an upstanding post on the table of the machinenormally used in said prior machine, may be dispensed with since thetransfer mechanism will always locate a bundle of mail precisely in thesame place on the table of the first tying machine 42. The tripmechanism disclosed in the aforesaid patent may be modified in form, butnot in function, as will hereinafter appear, to enable an automaticsensing mechanism to sense the absence of a bundle on the machine andthereby to halt all subsequent operations of the tying machines andassociated mechanisms.

Referring now to FIGS. 15, 16, 19 and 20, the modications of, andadditions to, the tying machine of the Bunn patent will now bedescribed. Said machine includes a frame 125, shown in dotted outline,on which is supported a bundle-receiving table top 126. In accordancewith the teachings in the aforesaid Bunn patent, operation of themachine is initiated by la lever 127 which has a portion 1128 extendingabove the surface of table top 126. Said lever portion 128 is in theform of a knob so that the length of the lever protruding above tabletop 126 is considerably reduced over that of the corresponding lever inthe aforesaid patent.

Above lever 123 is a hold-down mechanism comprising a wide angle yoke129 having diverging arms 130 and 131. Yoke 129 is supported from a bar132 which, in turn, is secured to the lower end of the piston rod 133 ofa pneumatic cylinder 134 of known construction, said cylinder, in turn,being rigidly secured to an angle iron 135 (FIG. 28) secured to frame125. A guide rod 136 prevents bar 132 from turning about the axis ofpiston rod 133 and hence maintains yoke 129 in a predetermined alignedposition over lever 127.

The twine arm 137 of the tying machine is substantially identical to thecorresponding twine arm of the tying machine of the aforesaid Bunnpatent and is adapted to swing in a circle shown in dotted line in FiG.20 to tie a reach of twine 138 around a bundle of letters in onedirection. As arranged in the present apparatus, the first tying machine42 will wrap a reach of twine around the long dimension of the bundle ofenvelopes.

FIGS. and 16 show the raised and lowered positions, respectively, of thehold-down mechanism when there is no bundle on the tabie top 126. It maybe observed from FG. 16 that in the lowermost position of the yoke I129,knob 128 of lever 127, though extending to a line 139 connecting thelowermost points of the diverging arms 138' and 131, is nevertheless notcontacted by the yoke and hence is not depressed to initiate theoperation of the tying machine. By making the subsequent operations ofthe apparatus dependent upon the functioning of tying machine 42, thefailure of the machine to operate under the conditions disclosed in FIG.16 provides the control necessary to effect the aforesaid desiredresult.

Referring now to FIGS. 19 and 20, the uppermost and lowermost positionsof yoke 129 when a bundle of mail has been placed upon table top 126over lever 127 are depicted. It may be observed from FIG. 19 that themere weight of the bundle 141i is not suicient to cause the lever 127 tobe depressed to operative position. Upon the actuation of cylinder 134to push piston rod 133, bar i132 and yoke 129 downward against bundle14d;

however, the increased pressure provided by the cylinder Willcause lever127 to be depressed, and the machine Yposed pneumatic cylinder 153.

will then be set into operation to cause twine arm 137 to wrap the twine138 around bundle 149 in the manner described in the aforesaid Bunnpatent.

The Second Transfer Mechanism The second transfer mechanism 43 (FIGUREl) is shown in FIGS. 27 and 28. It is comprised of a pneumatic cylinder141 of known construction mounted on a bracket 142 secured to machineframe 125. The operative end of said cylinder 141 is comprised of aplate 143 secured to the piston rod 144 of the cylinder so as to bemovable therewith. Inasmuch as the sole function of the transfermechanism 43 is to push bundle 149 from the first tying machine to thesecond tying machine, plate 143 may be circular in shape, and hence itis unnecessary that it be guided to prevent it from turning.

The location of the second Ytransfer mechanism 43 with respect to thetable top 126 is dictated by the clearance required between saidtransfer mechanism and a bundle of letters as it is being swung in anarc from a conveyor bucket 61 to the table top 126 of the first tyingmachine. The axis of the cylinder I141 is disposed to direct a tiedbundle of mail from the first tying machine to the proper location onrthe second tying machine for effecting a cross tie of the bundle at thedesired location thereon.

The Second Tying Machine The second tying machine 44 may besubstantially identical with the first tying machine 42. 1t is disposedat right angles to the first tying machine, and with its table top nohigher than, and immediately adjacent to, the table top 126 of the firsttying machine. As shown in FIGS. 17, 18, 21 and 22, the second tyingmachine 44 is provided with a table top 145 similar to table top 126 ofthe first tying machine 42 through which extends a trip lever 146, thefree end of which is formed as a knob 147, which is to be contacted by abundle of mail. Immediately over knob 147 is disposed a yoke 14S havingdiverging arms 149 and 151i defining between them a notch into whichknob v147 may extend without contacting the yoke. Since the second tyingmachine is designed to tie the bundle of mail across the short dimensionthereof, the length of the yoke arms 149 and 15b is considerably lessthan that of yoke 129 of the first tying machine.

Yoke 148 is mounted on the end of a bar 151 which, in turn, is secured.to the lower end, as Viewed in FIG. 18, for example, of the piston rod152 of a vertically dis- Said cylinder 153, as shown more clearly inFiG. 28, is rigidly secured to a bracket 154 which, in turn, is bolted,or otherwise secured, to an upstanding angle iron 155 boited to frame156 of the second tying machine '44. A mide rod 157 (FIG. :18) serves toprevent bar 151 from rotating about the axis of piston rod 152 and hencemaintains yoke 148 in proper position crosswise of a bundle to be tied.

FIG. 17 shows the second tying machine with the yoke 148 elevated toreceive thereunder a bundle of mail to be tied. FIG. 18 shows the secondtying machine with the yoke 148 in its lowermost position without abundle having been inserted thereunder. Under these conditions yoke 148does not contact knob 147 and hence the trip mechanism is not depressedto initiate the operation of the machine. In FIG. 21, bundle 141i hasbeen pushed upon the ltable top and upon knob 147 and under yoke 148. Asin the first tying machine, the weight of the bundle is not sufiicientto depress lever 146 and hence cross-tying machine 44 will not be set inoperation by the mere presence of a bundle on lever 146. FIG. 22 showsthe yoke 148 lowered upon bundle 141B and pressed thereagainst bycylinder 153, the pressure of the cylinder being sufficient to depress-trip lever 146, through contact between knob 147 and bundle 14d, toinitiate the operation of the machine. As shown by the dotted arrows inFIG.

aosaeo `22, the end of lthe twine arm 158 of the machine will describe acircle around bundle 140, thereby tying a reach of twine 159therearound.

The Third Transfer Mechanism After the second tying machine 44 hascompleted its operation, it is necessary to remove the tied bundle Ifromits table top to make room for the next bundle. The removal of the tiedbundle is effected by transfer mechanism 45 which is shown to bestadvantage in FIGS. 27 and 28. Said transferV mechanism may besubstantially identical to second transfer mechanism 43 and is comprisedof a pneumatic cylinder 168 `supported at its end regions from brackets161 and 162 similar in construction to bracket 142 associated withcylinder 141 and converging downwardly against a frame member 163 of thesecond tying machine 44 to which they are bolted. The control mechanism164 for cylinder 160 is mounted above ysaid cylinder on a verticallydisposed bracket 165 secured to a special frame member 166 the functionof which is to secure the two tying machines and the rst transfermechanism together to form a unit. Said cylinder 168 has a piston rod167 which is reciprocable across the table top 168 of the second tyingmachine 44 `and has secured to the end thereof a plate 169 disposedtransversely of the axis of the piston rod and of substantially the sameconfiguration as plate 143 of cylinder 141 for the purpose of contactinga tied bundle and pushing said bundle olf table top 168.

The Frame The conveyor 48, first transfer mechanism 41 and the tyingmachines 42 and 44 are united into a single structure by a frame whichincludes at the lower portion thereof the horizontally disposed angleiron 106 previously referred to and which, as seen in FIGS. 27 and 28,extends around the lower portion of both tying machines and is securedto said tying machines by suitable bolt fasteners 170. Said angle ironmay be bent in the form of connected rectangles which are supported fromthe floor through channel posts 171, 172, 173 and 174. Said posts aremade vertically adjustable by known means with respect to angle iron 106to allow for varying the height of the conveyor from the floor and totake care of irregularities in the level of the floor on which themachine is mounted. Angle iron 186 extends from plate 195, to which itis secured, across to the portion 175 (FIG. 27) of the frame at thelower regions of the first tying machine through a section 176 (FIG.28), thereby giving horizontal `support to the lower region of saidplate 185. The vangle iron frame is secured toframe 177 of the conveyorthrough a pair of lower brackets 178, 179 (FIGS. 27 and 28) which extendaround, and are secured to, plate 185 at the lower regions thereof, and

by a pair of upper straps 180, 181 secured to conveyor frame 177 at oneend, Iand at their other ends to angle iron 187 which is bolted to thesecond bearing 109.

It may be noted that the bundle to be tied, 140, is shown in dot-dashoutline in FIG. 27 in the positions it occupies in each of the tyingmachines 42 and 44. It may be noted yfurther that it is important thatsaid bundle 140 assume a predetermined position on the second tyingmachine 44 so that the twine will be tied around said bundle at apredetermined location on the bundle. lInasmuch as the transfermechanism 43 imparts considerable momentum to the bundle as it movessaid bundle `from the first tying machine 42 to the second tying machine44, Y

the latter is provided with a backstop 182 which is a standardconstruction for such tying machines as will be apparent by reference tothe machine shown in the aforesaid Bunn patent. Said backstop limitsmovement of the bundle to the left as viewed in FIGS. 27 `and 28. Ifsufficient momentum is given the bundle, the latter may tend to springback away from backstop 182, and hence it may be |desirable to lower thetable top 168 for the second tying machine 44 with respect to the tabletop 126 for the first tying machine 42 rather than have the two tabletops at the 'same level. In this manner the bundle, in rebounding fromthe backstop 182, will be stopped by edge 126a of the table top 126 andhence will be prevented from assuming an undesirable position on thetable top 168 of the second tying machine. Alternatively, it may vbedesirable to tilt the second tying machine 44 with respect to the iirsttying machine 42 in such manner that table top 168 slopes downwardtoward backstop 182, and hence any bundle resting on table top 168 willnormally slide toward, and come to rest at, backstop 182.

The Controls The `controls for the pneumatic cylinders, as statedpreviously, are solenoid-operated valves of a known construction whichvalves in turn are rendered operative by fifteen switches of themicro-switch type, closed by the movement of various elements of themachine as will hereinafter be described. In addition to thesolenoid-operated valves are the two mechanical trip devices, eachassociated with one of the tying machines, said trip devices functioningto set into operation a clutch of the tying machine which drives thetying arm and knotter of the tying machine. It is contemplated that themotor of each tying machine will be operated continuously from amanually operated master switch, but that the operation of theindividual tying arms and knotters will be intermittent and controlledsolely by their associated trip mechanisms.

The solenoid-operated valves used herein are of a type which is readilyavailable commercially. Two forms are shown for illustrative purposes inFIGS. 32 and 33, respectively, the FIG. 32 form being used where thepiston rod is to be extended as long as current is applied to itscontrol solenoid and then automatically red tracte-d, and the FIG. 33form being used where an instantaneous pulse of current is applied toone of two control solenoids to operate and hold the piston rod in oneor the other of its extreme positions. The valves and valve bodies forboth forms may -be identical and will be given the same referencecharacters herein.

Referring to FIG. 32, the typical cylinder wall is shown yat 240 and thecylinder is closed at one end by a machined head 241 which extendsoutwardly of the cylinder to form a portion of a valve body 242. A slidevalve 243 is reciprocable in a valve chamber 244 which is continuouslyexposed to air under pressure and through which said air under pressureis conducted to one side or the other of the cylinder. A pair of exhaustports 245 is formed in valve body portion 242 and communicates withvalve chamber 244. A port 246 connects valve chamber 244 with one end ofcylinder 240 and a port 247 connects valve chamber 244 with the otherend of cylinder 240 (not shown) through a pipe 248. Valve 243 is shownin a neutral position which, however, it never occupies when thecylinder is in operation; it is always either in its lowermost positionas viewed in FIG. 32 in which it connects port 246 to vent port 245, orin its uppermost position as viewed in FIG. 32 in which it connects port247 to vent port 245. In the former position, air under pressure isadmitted around the exterior of valve 243 to port 247 and in the latterposition, air under pressure is admitted to port 246.

The position of Valve 243 is controlled by a plunger 249 slidable in abore 250 in the outer portion 251 of the valve block and connected tovalve 243 by -a tonguefand-groove connection 252. Said bore is closed atone end by a plug 253. Plunger 249 is exposed on one side 253 to airunder pressure from chamber 244 through suitable passages (not shown) sothat the plunger is continuously biased to its lowermost position (FIG.32) in which air under pressure is admitted to pipe 248 to hold thepiston rod in its retracted position. A solenoid 254 is mounted on outervalve body portion 251 and its armature 255 is press fitted into anappropriate opening in plunger 249 to compel said plunger to move withits armature. Energization of solenoid 254 causes armature 255 to movedownwardly in bore 2511 as viewed in FIG. 32 against the air pressureexerted in the opposite direction -against end 254. Armature 255 remainsin its lower positionl only as long as solenoid 254 is energized.

In FIG. 33 the head 241, valve 243, plunger 249 and solenoid 254 are thesame as in FIG. 32, but a second solenoid 256 has been substituted forthe plug 253, and plunger 249 is balanced as to air pressure so that itsposition in bore 251i is determined solely by the energization ofsolenoids 254 and 256. When either solenoid 254 or 256 is energized,plunger 249 will move away from the energized solenoid and will staythere. Thus, solenoids 254 and 256 need be energized only long enough tomove their respective armatures to the limit of the movement permittedplunger 249, regardless of the instantaneous position of the piston andpiston rod in the associated cylinder, and since valve 243 remains inone or the other of its extreme positions, a complete operation of thecylinder, i.e., of the piston and piston rod is assured.

A rst group of five switches is shown in FIG. 3l and is mounted on aplate 183 shown in dotted outlines in FIG. 3l and fixed to the frame 49of the conveyor unit 4t?. Said plate 183 is preferably mounted inproximity to the upper sprocket 71 of the conveyor (FIG. 28) and inproximity to the path of movement of three pins 184, 185 and 156 mountedon the face of sprocket 71 and extending laterally therefrom. In theform chosen to illustrate this invention, the linear distance betweenadjacent buckets 61 on conveyor chains 54 and 55 (FIG. 5) is exactlyone-third the circumference or sprocket '71, and hence, the cycle ofpicking off a bundle of mail from conveyor 4t? occurs three times duringa single rotation of sprocket 71. It is for this reason that three pinsare used, said pins, accordingly, angularly spaced 120 apart.

The tive switches in the rst group are shown (FIG. 3 l) arranged in anarc of a circle at 187, 128, 1259, 1911 and 191, the switch-operatingportions of which are shown at 192, 193, 194, 195 and 196. Saidoperating portions may comprise the usual rollers (not shown) which arecontactedby said pins 184, 185 and 186 as they are rotated past theswitches.

The second group of switches (FIG. 11a) comprises three mounted on frame125 of the tirst tying machine 42 in proximity to the mutilated gear 197of said tying machine 42. The details of construction of said mutilatedgear are shown in detail in the aforesaid Bunn patent and will not begiven here. Said second group is shown at 198, 199 and 2111i, each beinglocated at a different radial distance from one another so that eachwill be activated but once during the rotation of the mutilated gear. Asis more fully described in the aforesaid Bunn patent, mutilated gear 197rotates only after the trip mechanism associated with tying machine 42has been activated and its associated clutch has been operated. Theangular spacing between the switches 198, 199 and 201i is dictated moreby convenience of location on the frame 125 than by any timingrequirements inasmuchas each switch is operated by its own pin 201, camv222 and pin 2193 mounted at different radial distances on mutilatedgear 197, and hence the location of the pins and cam may be selected,one with reference to the other, to give the desired sequence ofoperation.

The third group of switches (FIG. 14a) comprises two in number which aremounted on the frame 156 of the second tying machine 44. These switchesare shown at24 and 205 disposed at ldiderent radial distances from oneanother and adapted to be contacted by their respective pin 266 and cam2117 mounted on the corresponding mutilated gear 208 of the tyingmachine 44. Here again the vlocation of the switches 204 and 2115 isdictated more by convenience of attachment to a frame member than bycyclic timing inasmuch as the latter may be regulated by appropriatelocation of the individual pin 206 and cam 207.

A fourth group of switches has already been referred to and isassociated with the -first transfer mechanism 41. The iirst of these isswitch 209 shown in FIG. 29 mounted on casting 108 and having anoperative element 210 adapted to be contacted by finger 101 mounted onthe end 1110 of guide rod 97. The second and third switches are shown inFIG. 27 at 211 and 212 having, respectively, operative elements 213 and214 adapted to be contacted by a pin 215 shown in FIGS. 28 and 29 asdepending from the base 95.

A fifth and last group of switches is shown schematically in FIG. ll at216 and 217, these switches and their loperative members being mountedon the frame member 135 (IFIG. 28) and contacted by a portion of theholddown mechanism 129 which is reciprocated by cylinder 134.VPreferably the -said switches are mounted adjacent the guide rod Aforthe hold-down mechanism and operated by an extension thereon.

The several cylinders 118, 9S, S6, 115, 134, 141, 153 and 160 and theircontrol switches are shown schematically in FIG. 34. In that ligurethere is shown a pipe 218 which conducts air from a suitable source ofair under pressure (not shown) fto the usual trap 219 and through ashort pipe 225 to a pressure regulator 221. Said pressure regulator isconnected through a short pipe 222 to an oiler 223 which in tum isconnected `to a header 224. Said header is connected through branchlines numbered 225 to 2.31, inclusive, to cylinders 160, 153, 141, 134,115, 98 and 113, respectively. Cylinder 86 provides the pressure forcontacting a bundle of mail and hence, to avoid exerting destructivepressure upon the mail, is designed to operate at a lesser pressure thanthe remaining cylinders. Accordingly, a branch line 232 is connected toa pressure reducer and regulator 233, from which the air passes througha pipe 234 to cylinder 86.

It is understood that interposed between each header and its cylinder isa solenoid-operated valve of the type shown in FIGS. 32 or 33 whichcontrols the ac-tual flow of the air under pressure to and from eachcylinder. Cylinders 118, 98, S6, 115, 134 and 15.3 are of the type shownin FIG. 33 and have a separate solenoid for controlling movement of theassociated piston in each direction; that is, one solenoid controlsmovement of the piston rod associated with the enclosed piston out ofthe cylinder, and the other solenoid controls the return movement of thepiston rod into the cylinder. Cylinders 141. Iand 160 utilize a solenoidof the type shown in FIG. 32 which automatically reverses the airconnections upon release of the energizing coil switch so that thepiston rod retracts into the cylinder soon after it reaches itsoutermost excursion out of the cylinder. It may be recalled thatcylinders 141 and 160 are associated with the second and third transfermechanisms which serve'merely to push a bundle of mail from one tyingmachine to the other, or to eject a tied bundle from the second tyingmachine,

Y and hence there is no requirement that the extended rod remain in suchposition for any length of time.

Energy for the solenoids is derived `from a common line 235 which may bethe usual volts, 60 cycle line. One side 236 is connected to each of theswitches, and the other side of the line 237 is connected directly tothe solenoid controlled by-each of the switches. The switches thus arein series with their solenoids.

It may be 4observed that Ithe solenoids 238 and 239, controlling thereturn of the pistons 4and their associated connecting rods of cylinders113` and 115, are controlled by the same switch 187. It may be notedfurther that movement `of the piston rod for cylinder 98 out of saidcylinder is controlled by two separate switches 188 and 211 and that thereturn of the piston 4rod to said cylinder 98 is controlled by threeswitches, 1911, 217 and 198, the said threel switches also controllingthe withdrawal or raising of the hold-down mechanism 129 associated withthe iirst tying machine. The reasons for these intercon- V nectedswitches will be madeapparent hereinafter.

13 Operation The operation of the machine will now be described withreference to the rschematic `drawings shown in FIG. 3 to 14a inclusiveto which reference is now made. For ease of description, the U-shapedstamping 90 shown in FIG. 8 will be called hereinafter a pick-off head.

It is understood that the conveyor 40, after having been previously setinto operation by its drive motor 78 and then subsequently stopped, maycome to rest with its sprocket 71 in any one of an infinite number ofangular positions with reference to the frame of the conveyor. Forpurposes tof illustration, however, it will be assumed that initiallythe pick-off head is at its highest point with reference to the machineframe and has been moved back away from the vertical lsection 48 of theconveyor. This posi-tion is shown in FIGS. 3 and 4. Assuming now thatthe conveyor motor 78 is energized and the conveyor is set in motionwith the `chains and buckets thereof moving toward the vertical section48, a pin 184 on the sprocket wheel 71 will contact the switch operatorof micro-switch 187, causing the vertically disposed cylinder 118 toretract its piston rod and thereby lower the pick-off head 90. Thelowered position of the head is shown in FIG. 6. While the head wasbeing lowered, the conveyor continued to move and sprocket 71 broughtpin 184 into contact with the operative portion 193 of micro-switch 188.This caused the pis-ton rod for cylinder 98 to be extended to bring thehead 90 to a bundle of mail. In reality, due to the proximity of theswitches 187 and 1188, the movement of the head toward the bundleoverlaps the las-t portion of the downward movement of the head so thatthe head moves toward in synchronism with the movement of the bundlealong the ver-tical portion of the conveyor While at the same timemoving in tow-ard a bundle. The position of the head around the portionof the bundle protruding .out of a conveyor bucket is shown in FIG. 8,the corresponding plan view being shown in FIG. 7. The head is now readyto clamp a bundle and this operation takes place next, dueto themovement of nger 101 against the operative portion 210 of micro-switch209. The operation of the clamping cylinder 86 is shown in FIG. 8a.

After the bundle is firmly cl-amped by the cylinder 86, pin 184 willhave `contacted the operative end 195 of micro-switch 190, therebyenergizing the solenoid for cylinder 9S. This retracts the pistonthereof into said cylinder, thereby pulling the clamped bundle away fromthe conveyor and out of the bucket in which it was retained. Continuedrotation of the sprocket wheel 71 brings the pin 184 into Contact withthe operative end 196 of microswitch 191'which energizes the controlvalve solenoid of cylinder 115 of the first transfer mechanism. Thiscylinder rotates the pick-E head with the clamped bundle in it through90 to the first tying machine 42. This is rshown in FIGS. 9 and 10. Asthe cylinder 115 is rotating the pick-olf head to the iirst tyingmachine, the operative ends 213 and 214 of switches 211 and 212 arecontacted by pin 215 mounted on base 95. Switch 211 being in parallelwi-th switch 188, performs the identical function as switch 18S andcauses the cylinder 98 to extend its rod and the associated head towardthe tying machine while the cylinder 115 is swinging the pick-off headtoward the ltying machine as stated above.

Switch 212 controls the hold-down mechanism operated by cylinder 1134.It is desirable, of course, that the bundle be properly located on thetying machine before it is clamped by the hold-down mechanism 129, andhence switch 211 is operated in yadvance of switch 212. It is alsoessential that the Ibundle be in place before the tying operationcommences. Since the pressure of the holddown cylinder 134 is reliedupon to operate the trip lever 127, this provides additional reason forcausing switch 211 to be operated before switch 212.

As the cylinder 134 i-s operated to lower the hold-down mechanism uponthe transferred bundle, it actuates switches 216 and 217. Switch 216controls the raising of the clamping cylinder from the bundle and switch217 duplicates the function `of switch 190 and therefore serves towi-thdraw the head linearly from the bundle. By this time, the next -pin186 on sprocket 71 has contacted the operative end 192 of switch 187which causes the piston rod and cylinder 11S to be extended to raise thehead at the same time that the cylinder is rotating the head back to aposition confronting the vertical section 48 of the conveyor. Thisbrings the pick-off head back to its starting position.

Although the pick-off head has described a complete cycle of operation,the bundle is only in its rst tying position on the rst tying machine.It may be recalled that when the cylinder 134 Iwas operated to lower thehold-down mechanism 129 upon the bundle, and the bundle thereuponoperated the ltrip mechanism for the machine, the tying operation forthernachine was commenced which involved the rotation of the mutilatedgear 197 of the first tying machine to cause the sequential operation ofthe switches to be contacted by the pin 291, cam 202 and pin 203- onsaid mutilated gear. The rotation of the mutilated gear brings the pin201 into contact with the operative portion of switch 198 which causescylinder 134 to raise the hold-down 129 from the bundle and release thebundle lfor its transfer to the next tying machine, and at the ysametime, as shown in FIG. 34, causes cylinder 9S to be `operated towithdraw the head from the tying machine.

rContinued rotation of the mutilated gear next brings cam 2112 intocontact with the operative portion of switch 199 which causes thesolenoid-'operated valve for cylinder 141 to operate to admit air underpressure to that cylinder in the manner hereinabove described to causean extension and retraction Iof its piston and associated rod, wherebyto transfer the tied bundle from the first tying machine 42 to thesecond tying machine 44. Cam 202 will hold switch 199 operative untilthe lbundle has been completely ejected. Still `further rotation of themutilated gear causes pin 203 to contact the opera-tive portion ofswitch 200 to result in the operation of cylinder 153 associated withthe second tying machine 44 and thereby to bring the hold-down mechanismof that cylinder against the transferred bundle on the second tyingmachine 44.

FIGS. 12 and 13 show the bundle in place on the second tying machine,and FIG. 14 shows the hold-down mechanism 148 for the second tyingmachine operated which, as previously described, exerts pressure uponthe bundle ,to depress the trip lever 146 of the second tying machineand thus initiates the operation of the said second tying machine.During the operation of said second tying machine, mutilated gear 2118thereof will be rotated and will cause contact to be established betweenthe pin 206 carried by said gear and the operative portion of switch 204to close said switch. This energizes the solenoid valve for cylinder 153and results in an operation of the cylinder to lretract hold-downmechanism 14S toffee the tied bundle. Further rotation of mutilated gear298 causes cam 297 movable therewith to contact the operative portion ofswitch 295 which, as seen in FIG. 34, con- Itrols the solenoid forcylinder 160, the function of the latter being to eject the tied bundlefrom the second tying machine. The said cylinder will be operated tocause an extension of its rod and a retraction thereof in the mannerdescribed with reference to cylinder 141 and thus to complete the cycleas to the tied bundle. Cam 207 will hold switch 205 in `operativeconditi-on long enough to insure a complete ejection of the tied bundlefrom the machine.

During the operation of the second tyingrrrachine, the conveyor 4t), ofcourse, has been continuously and steadily moving toward the transfermechanism, and with the movement of the conveyor, there has been acontinuous and steady rotation of the sprocket 71, with pin 186 passingsequentially from one to lanother of the operative portions 193, 19d,1%' and 1% of the switches 33, 139, 19) and 193i to perform thetransferring cycle by which la bundle is picked oif the conveyor fandplaced upon :the first tying machine 42. Thus, as soon as a bundle hasbeen tied by the first tying machine 452 and ejected therefrom, a secondbundle is transferred from the conveyor to said first tying machine sothat the lirst and second tying machines are operating substantiallysimultaneous-ly. The interval between tying operations for the machinesis thus controlled by the speed with which a bundle may be transferredfrom the conveyor to the first tying machine.

As a `safety measure, it is desirable to make certain that the holdfdownmechanism 148 of the second tying machine 44 is in its raised positionwhile a bundle is being transferred from the tirst tying machine 42 to.the second machine di. An additional switch 257 is mounted on the framefof the rst tying machine 42 (FlG. lla) to be contacted `by a pin 258 onmutilated gear 197 thereof and timed to raise the vhold-down mechanism143 just before mechanism i3 begins to operate.

Referring now to FlG. 35, there is shown a sequence `and timingdiagramfor all of the operations performed by the tying machines and transfermechanisms. The diagram is in the form of a chart, the horizontal scalereferring lto equal increments of movement of the conveyor (eachincrement representing one inch of movement in the form chosen toillustrate this invention) and the numbers arranged verticallycorresponding to the switches which are to be operated. The heavy linesshow the operations of the cylinders, the time when they are operated,and the duration of each operation. The arrows yat the ends of thecylinder designations indicate the direction in which the piston rodsthereof are moved.

lt may :be noted from the dotted representation of the repeating cyclesthat there is an `overlap between the operation of the first tyingmachine and the second tying machine in the manner hereinabove describedwhereby said machines are made -to operate at substantially theirmaximum capacity. This makes for a most eiiicient opera-tion 'of themachines.

I claim:

l. In combination, a frame, conveyor means on said frame for movingbundles of mail from one or more assembly stations to a pick-offstation, means on the fname for tying la bundle of mail together, meanson the frame at the pick-olf station for seizing 'a moving bundle, meansfor transferring a seized bundle from the conveyor means to apre-determined location on the tying means, control means movable intimed relation with the conveyor means, and means operated by saidcontrol means for initiating operation of the transfer means, saidconveyor means having a horizontal section and avertical section, saidvertical section being disposed at ythe pickeoff station, and saidtransfcrrmeans including a bundle pick-o head, means for lowering thepick-oif head in timed relation to the movement of the conveyor meansover said pick-off station, and means for moving the pick-off headtoward .and away from a bundle Ion said conveyor means.

2. In combination, a frame, `conveyor means on said frame for movingbundles of mail from one or more assembly stations to a pick-olfstation, means on the fname for tying a bundle of mail together, meanson the frame at the pick-off station for seizing a moving bundle, meansfor transferring a seized bundle from the conveyor means to apre-determined location on the tying means, control means movable intimed relation with the conveyor means, and means operated by saidcontrol means for initiating operation of the transfer means, saidconveyor means having a horizontal section and a vertical section, said-vertical section being disposed lat the pick-olf station, said transfermeans including a bundle picksoff head, means for moving the pick-offhead in timed relation to the movement of the conveyor means over saidpick-off section, means yfor moving the piclfoff head toward and awayfrom a bundle on the conveyor means, clamping 16 means on said pick-offhead for seizing a bundle of mail on said conveyor means, and meansoperated by the means for moving the pick-off head toward and atvay fromla bundle for initiating the openation of said clamping means.

3. `In combination, la fra-me, :conveyor means on said frame for movingbundles of mail from one or more assembly stations to a picloof station,means on the frame for tying a bundle of mail together, means on theframe `at the pick-off station for seizing a moving bundle, means fortransferring a seized bundle from the conveyor means to a pre-determinedlocation on the tying means, control means movable in timed relationwith the conveyor means, and means operated by said control means forinitiating operation of the transfer means, said tying means beingdisposed to one side of said conveyor means, said conveyor means havinga horizontal section land a vertical section wherein the conveyor meansmoves downwardly, said vertical section including the pick-off stationbeing adjacent the tying means, and said transfer means including abundle pick-olf head, means for lowering the pickoff head in timedrelation to the movement of the conveyor means over said pick-offstation, means on the pick-off head for seizing a bundle olf mail on theconveyor means while said pick-olf head is moving in timed relationthereto, and means for simultaneously withdrawing a seized bundle fromsaid conveyor means, rotating said bundle through toward the tying meansand lowering said bundle upon said tying means.

4. The combination described in claim 3 characterized by means operableupon movement of the transferring means to `a predetermined positionover the tying means for arresting the turning movement of said pick-olfhead and vfor withdrawing said pick-off head from :said tying means.

5. ln combination, VVa frame, conveyor means on said lframe for movingbundles of mail from one or more assembly stations to a pick-offstation, means on the frame for tying a bundle of mail together, meanson the frame at the pick-off station for seizing a moving bundle, meansfor transferring a seized bundle from the conveyor means to apre-determined location on the tying means, control means movable intimed relation with the conveyor means, and means operated by saidcontrol means for initiating operation of the transfer means, saidconveyor means for moving bundles of mail comprising la chain conveyorhaving a plurality of equally spaced mail receiving buckets thereon,each said bucket including a bottom wall, an opstanding end Wal-l and aside wall contacting the end and bottom Walls, said side wall beinginclined with respect to the bottom wall, and resilient means forholding a bundle of mail against said side wall.

6. In combination, a frame, conveyor means on said frame for movingbundles of mail from one or more assembly stations to a pick-offstation, means on the frame for tying a bundle of mail together, meanson the frame at the pick-off station for seizing a moving bundle, meansfor transferring a seized bundle from the conveyor means to apre-determined location on the tying means, control means movable intimed relation with the conveyor means, and means operated by saidcontrol means for initiating operation of the transfer means, saidconveyor means for moving bundles lof mail comprising a chain conveyorhaving a horizontal section and a vertical section, a plurality ofequally spaced buckets mounted on and movable with said chain conveyor,each said bucket comprising a wall disposed substantially in the planeof the chain conveyor, an end wall disposed substantially at rightangles with the first mentioned wall and a side wall connected yto therst and second mentioned walls and inclined with respect to the lirstmentioned wall such that as said bucket traverses the'vertical sectionof the conveyor means, mail disposed in said bucket will tend to :slidetoward said tirst-meutioned wall to be retained thereby.

7. The combination described in claim 6, the inclined

1. IN COMBINATION, A FRAME, CONVEYOR MEANS ON SAID FRAME FOR MOVINGBUNDLES OF MAIL FROM ONE OR MORE ASSEMBLY STATIONS TO A PICK-OFFSTATION, MEANS ON OR MORE ASSEMBLY STATIONS TO A PICK-OFF STATION, MEANSON THE FRAME FOR TYING A BUNDLE OF MAIL TOGETHER, MEANS ON THE FRAME ATTHE PICK-OFF STATION FOR SEIZING A MOVING BUNDLE, MEANS FOR TRANSFERRINGA SEIZED BUNDLE FROM THE CONVEYOR MEANS TO A PRE-DETERMINED LOCATION ONTHE TYING MEANS, CONTROL MEANS MOVABLE IN TIMED RELATION WITH THECONVEYOR MEANS, AND MEANS OPERATED BY SAID CONTROL MEANS FOR INITIATINGOPERATION OF THE TRANSFER MEANS, SAID CONVEYOR MEANS HAVING A HORIZONTALSECTION AND A VERTICAL SECTION, SAID VERTICAL SECTION BEING DISPOSED ATTHE PICK-OFF STATION, AND SAID TRANSFER MEANS INCLUDING A BUNDLEPICK-OFF HEAD, MEANS FOR LOWERING THE PICK-OFF HEAD IN TIMED RELATION TOTHE MOVEMENT OF THE CONVEYOR MEANS OVER SAID PICK-OFF STATION, AND MEANSFOR MOVING THE PICK-OFF HEAD TOWARD AND AWAY FROM A BUNDLE ON SAIDCONVEYOR MEANS.